Ergonomics in Dentistry: Optimizing Work Practices

Posted on Dec 19, 2024 in Physical Education

Ergonomics: Optimizing Work Practices in Dentistry

Ergonomics is a scientific discipline devoted to the study and analysis of human labor, especially the influence of anatomy, physiology, and other individual factors.

Objectives of Ergonomics

Choose technology according to the available staff.
Optimize human performance by improving their quality of life.
Simplify work processes.
Increase efficiency by reducing physical and mental fatigue and working time.
Study the workplace environment.
Promote the interests of the employee in their work.
Review the work environment.
Discover and minimize risks associated with fatigue.
Optimize the available personal technology.

Ergonomic Intervention Steps

1. Discover the problems that distort the job.
2. Search for new methods and conditions for staff.
3. Progressively implement possible solutions found to improve the work.
4. Check the effectiveness of changes and improvements in the quality of work by external criteria.

Areas of Action of Ergonomics

Value: Job-machine-user relationship.
Various: Machines and systems related to each user.
Preventive: Design and project planning.
Scans: Remedial actions to correct errors.
Geometric: Postures, movements, and environments.
Harmonize: Environmental light, sound, temperature, etc.
Optimize: Temporary timetables, rhythms, and other elements related to time.

With regard to the human body, measurement areas are basically of three types:

1. Anatomical

Structural or static (the body at rest)
Functional or dynamic (the body in motion)

2. Physiological

Protection and work environment (light, air, noise, temperature)
Personal space, labor, and equipment.

3. Psychology

Direct influence on the identity of the person, self-esteem, etc.

Work Areas in the Dental Office

ISO represents those areas in the face of a clock, placing the patient’s head in the center of the field and their feet at 6:00. From this point, there are areas of action for the dentist and the assistant, and another area shared by both.

Classification of Work Areas

1. Dentist Area: Between 8:00 and 12:00.
2. Support Staff Area: Between 1:00 and 4:00. This area is where materials and instruments are placed for transfer to the dentist.
3. Material and Instrument Transfer Zone: The area between 4:00 and 7:00.
4. Area Shared by the Two Components of Dental Equipment: Area between 12:00 and 1:00.
5. Area and Instrumental Materials: Between 5:00 and 8:00 to facilitate access to instruments for the dentist and staff.

Balanced Position for Dentists

The position in which the dentist performs procedures with greater precision and less physical fatigue, with movements of small amplitude.

Features:

1. Head in the most relaxed position possible.
2. Shoulders and arms relaxed and upright.
3. Forearms forming an angle between 45° and 90° with the hands.
4. Wrists aligned with the forearms.
5. Back maintaining the natural curvature.
6. Legs separated and tilted slightly downward.
7. Feet slightly apart and flat on the floor.

Ergonomic Position of the Dentist

The head should not be forced to avoid hyperextension. It is strongly recommended to maintain a minimum distance of 40cm between the head of the operator and the patient’s head. The elbows should be placed as close to the body as possible, with the forearms and arms forming a 90-degree angle. The spine should be upright.

Ergonomic Posture for Dental Assistants

The assistant should adopt a position higher than the dentist (about 15cm) and will sit on the dental stool so that their feet are flat on the floor or stand on the stool with their back against the backrest. To place the stool at the right height for work, the support staff should stand beside the chair and raise it until it reaches the height of their fibula. The patient is placed in a supine position to enter the professional level.

Movements Performed During Dental Procedures

Class I Movements: Only the fingers move.
Class II Movements: Fingers and wrist move.
Class III Movements: Fingers, wrist, and elbow move.
Class IV Movements: Arm moves from the shoulder.
Class V Movements: Arm and back move.

The movements of the first three classes are the most recommended for the team because they produce less fatigue and are conducted in a shorter time.

Instrument Transfer

The dentist has an active side (right for right-handed individuals) and a passive side (left), a dominant hand that performs the technique, and a non-dominant hand.
The support staff has an active side (left) and a passive side (right).

Ways to Pick Up an Instrument

Pencil Grip: Held with the tips of fingers 1, 2, and 3.
Modified Pencil Grip: Attached to the fingertips of 1 and 2, supporting the stem on the 3rd finger or a low point of the handle.
Palmar Grip: Situated in the palm of the hand to deliver or pick up.
Scissors Grip: Retrieved from the operator’s hand with fingers 4 and 5.

Precaution: The instrument should not be transferred at the eye level of the patient. All instruments capable of provoking tension or fear should be kept out of sight. The assistant takes the instrument with their left hand and deposits it in the dentist’s right hand.

Four-Handed Technique

This technique increases efficiency and reduces muscle tension. It is a technique performed in tandem with short, controlled strokes to achieve high performance and lower physical and mental fatigue.

Single Instrument Transfer

Wash hands and wear gloves.
Take the instrument from the tray with a 1, 2, 3 grip, from the third farthest from the active part.
Bring the instrument to the transfer area (about 5 cm from the patient’s mouth).
Place the instrument in the dominant hand of the dentist with the active part oriented toward the patient’s mouth.
Once used, the dentist will indicate the withdrawal orally.
Remove the instrument from the operator’s hand with a 1, 2, 3 grip and place it back into the tray.

Two-Instrument Exchange

Wash hands and wear gloves.
Deliver the first instrument as in the previous case.
The dentist will advise the change of instruments and request a new one.
Take the second instrument from the tray with a 1, 2, 3 grip.
Align the instrument with the dentist’s hand and place it parallel to the instrument they have in hand. Remove the first instrument with a 4, 5 grip and deliver the second.
Replace the first instrument in its place on the tray.
Remove the second instrument with a 1, 2, 3 grip when directed by the dentist.

Rotating Equipment Exchange

Wash hands and wear gloves.
Ensure the connection of instruments to the hose is correct.
Check the smooth actuator in the spittoon.
Use the left hand to guide the active instrument into the mouth of the patient.
Hand instruments to the dentist and remove them upon their indication.
Remove the instrument with the left hand and place it in the dental unit.

Instrumental Exchange of Articles

Wash hands and wear gloves.
Take the tray with the joint, its active part facing the auxiliary, and clamp it with a 1, 2, 3 grip.
The instrument is supplied with the handle in the palm of the dentist’s hand.
Collect upon the dentist’s indication.

Needle Exchange for Anesthesia

Wash hands and wear gloves.
Prepare and load the syringe.
Place the needle without removing the protector, offering it to the dentist so that the piston rings are toward the dentist’s hand and the needle is facing the assistant.
Once used, the dentist should recap the syringe before handing it back or leaving it in the tray.

Occupational Diseases in Dentistry

These are derived from both the working posture and the use of different materials and products. The diseases that components of the dental clinic can suffer are:

Infectious Diseases: The most common are respiratory, such as tuberculosis. Viral infections such as AIDS, Hepatitis, Herpes, etc., can also occur.
Cardiovascular Diseases: Varicose veins, edema, etc. (especially if working standing up).
Hearing Disorders: Deafness caused by the noise of rotating materials.
Hypersensitivity to Dental Materials: Dermatitis, allergies to latex, or certain disinfectants.
Mercury Toxicity: The most common route is through inhalation or skin contact. Mercury accumulates, leading to acute or chronic disorders.
Osteoarthritis: Primarily in the ankles, knees, hips, and spine; neck injuries, muscle spasms, etc.
Other Changes: Ocular trauma from instrumentation or glare, eyestrain, etc.